National Repository of Grey Literature 10 records found  Search took 0.01 seconds. 
Laboratory workplace for measuring performances of DVB-T2/T2-Lite
Krejčíř, Dominik ; Kufa, Jan (referee) ; Polák, Ladislav (advisor)
This thesis deals with proposal and realization an appropriate measurement workplace to measure performances of DVB-T2 and DVB-T2-Lite. Both systems for terrestrial digital video broadcasting are described. It is possible to measure objective parameters and evaluate the quality of DVB-T2/T2-Lite signal subjectively. The proposed concept was verified by a set of experimental measurements, which is divided into four scenarios. The measurement focuses to parameters of Set-Top-Boxes. The measurement allows to test and compare Set-Top-Boxes.
On The Performance Of Objective Video Quality Metrics For Uhd Videos
Kufa, Jan
This paper deals with the performance evaluation of different objective metrics, used for the assessment of Ultra HD (UHD) video quality. Video sequences are compressed by HEVC video encoder. Objective scores are compared to each other and verified by scores from subjective tests. Such a comparison is completed by a simple correlation analysis. Differences between the objective scores obtained from the metrics implemented in the HEVC encoder and independent tool are explored in the second part of this paper. The PSNR metric is considered in this case.
Video and Data Services Quality in the Future Broadband Multimedia Systems and Networks
Kufa, Jan ; Hudec, Róbert (referee) ; Fliegel,, Karel (referee) ; Kratochvíl, Tomáš (advisor)
Téma doktorské práce je zaměřeno na analýzu zpracování signálů v širokopásmových multimediálních sítích a systémech budoucnosti, kde se předpokládají systémy s ultra vysokým rozlišením (UHDTV), vysokým snímkovým kmitočtem (HFR) a stereoskopické systémy (3D). Tyto systémy budou umožňovat vysoce účinnou zdrojovou kompresi obrazu, zvuku a dat a také jejich vysoce účinný přenos, a to jak při volném vysílání (např. DVB-T2), tak ve službách placené televize (např. IPTV). Cílem práce je analýza a vyhodnocení kvality obrazu a služeb v těchto systémech na základě objektivních metrik a subjektivních testů. Práce se dále zaměřuje na analýzu vnímané kvality u stereoskopické televize, kódovací účinnost moderních stereoskopických enkoderů a vlivu sekvencí na uživatelský komfort.
Predefined Quality Profiles in Different Versions of HEVC Encoder - Influence of PC Architecture of Processor
Kufa, Jan
This paper describes a coding efficiency of the High Efficiency Video Coding (HEVC) encoder with different predefined quality profiles. To increase the encoding speed of the video at the same bitrate we can use either other implementation of the encoder or we can set different predefined quality profiles. The x265 is the implementation of the coding standard HEVC. This article complements of our previous exploration of predefined x265 profiles. There is explored the influence of processor architecture and version of x265 implementation on the speed of encoding and on the performance of video quality.
Subjective tests of influence of the content of the scene on the spatial effect of 3D images and videos
Kaučiarik, Filip ; Kufa, Jan (referee) ; Boleček, Libor (advisor)
This thesis is concerning with study of video sequence parameters which influence the quality of picture during watching 3D frames and videos. It´s focused on comparing individual parameters of video sequences which are spatial and temporal information and depth map range and their influence on subjective testing and assessment of quality of experience by respondents . This thesis contains specification of testing sequence plan based on diversity of video sequence parameters and also a layout of subjective testing. An absolute parameter J was determined to achieve the maximum effect of objective parameters of sequency to 3D effect and comfort of the scene within subjective assessment.
Accumulator Charger for Bicycle
Kufa, Jan ; Kubíček, Michal (referee) ; Šebesta, Jiří (advisor)
The aim of this thesis is to suggest a suitable way of charging mobile devices by using bicycle. In the first part of bachelor thesis there are discussed various options for charging the battery on a bicycle, described differences between the alternator and dynamo, and finally the different types of batteries. The second part describes in detail used blocks that were used in the engagement and the reasons of their choice. In the last section there are described the final parameters of the charger.
Subjective video quality tests on Ultra HDTV video sequences
Stavěl, Marek ; Fliegel, Karel (referee) ; Kufa, Jan (advisor)
This semestral thesis describes the possibilities of source coding videos, the attributes of the videos and their recommended changes for test. Subjective methods of scores of quality and their division into metrics with references and without references are delineated. In this work, a draft of videos for test of comparison of set metrics is specified here. Further, the coding and options of attributes of videosequences for scoring of the quality of the picture is presented. The displaying system is described and quazicrowdsorcing system of collecting the datas was created.
Comparison of objective and subjective video quality metrics for Ultra HDTV sequences
Bršel, Boris ; Krasula, Lukáš (referee) ; Kufa, Jan (advisor)
Master's thesis deals with the assessment of quality of Ultra HDTV video sequences applying objective metrics. Thesis theoretically describes coding of selected codecs H.265/HEVC and VP9, objective video quality metrics and also subjective methods for assessment of the video sequences quality. Next chapter deals with the implementation of the H.265/HEVC and the VP9 codecs at selected video sequences in the raw format from which arises the test sequences database. Quality of these videos is measured afterwards by objective metrics and selected subjective method. These results are compared for the purpose of finding the most consistent correlations among objective metrics and subjective assessment.
Strategy for Improvement of Training System of Company
Gazurová, Anna ; Kufa, Jan (referee) ; Mallya, Thaddeus (advisor)
This thesis focuses on problems related with new graduates at the „Department of New Employees Training“ of TŘINECKÉ ŽELEZÁRNY joint stock Company. The work evaluates to what extent the participants are satisfied with the training period, work of each mentor assigned to them and how they are involved in solving concreate tasks. Later suggestions are made on what measures should be taken to improve the program, for future participants to be satisfied.
Shortwave power amplifier
Kufa, Jan ; Vařacha, František (referee) ; Prokeš, Aleš (advisor)
The aim of the master´s thesis is to create a high-frequency amplifier with switching power amplifier classes among classes A, B, C with output power of 10 W. The amplifier operates at frequency from 3.5 MHz to 14 MHz. Master´s thesis includes also theoretical analysis, design of lowpass filter and amplifiers and their simulation, mechanical realization and measured parameters of the amplifier.

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